Mechanical stoker



Jan. 10, 1939. F- REAM 2,143,743

MECHANICAL STOKER v Filed Oct. 2 1936 2 Sheets-Sheet 2 IN VENTOR, :M lW,

,%.; ATTORNEY Patented Jan. .10, 1939.

UNITED STATES PATENT OFFICE ton,

Ohio

Application October 2, 1936, Serial No. 103,634

3 Claims. (01. 83-52) This invention relates to new andprovements inmechanical stokers, and more particularly to the type of stokerillustrated and described in my application for United States LettersPatent, Serial No. 76,651, filed April 27th, 1936, distinguishing fromthe latter in that in the present case the bottom is mounted for aswinging movement about. the feed screw.

It is one 01 the principal objects of this invention to provide aswinging bottom below the usual feed worm shaft in mechanical stokers,to keep the material in constant agitation throughout the hopper.

Frequently in automatic coal stokers of the underfeed type,v in usingfine, damp or dirty coal, or coal having roots, leaves or other foreignmatter intermixed therein, such material packs in the throat of thehopper, thereby bridging over,

and shutting oifthe supply of such material, to the feed screw. Theresult is a diminished or suspended supply of such material to theretort,

with attendant discomfort and annoyance.

Similar interruptions necessarily ensue in the normal delivery ofmaterial to the retort by the feed screw in the case of lump coal, whenlumps which are too large to pass through the feed tube become numerousaround the feed screw, thereby bridging over the latter and restrainingany finer material 'which might lie above the lumps from reaching thefeed screw.

My swinging bottom constantly maintains a seam or cleavage in thematerial in a vertical plane extending longitudinally with the axis ofthe feed screw, and directly above the same, whereby such material,embodying loose particles, will gravitate without hindrance directlyinto the ,path of the feed screw.

It is a further object of my invention to provide means whereby myswinging bottom may be actuated by the feed screw shaft.

. Another object of my invention is the provision of a swinging bottomwhich may be made as a single integral casting including the lower halfof the crusher cone, with the upper half of the cone detachablyconnected thereto for removal to permit the withdrawal of obstructions.and the making of repairs. This bottom is mounted con centric with thefeed screw and feed tube, being useful imabove the feed screw to causeit to fall directly into the path of the same.

Other important and incidental objects will be brought out in thefollowing specification and particularly set forth in the subjoinedclaims.

In the accompanying drawings, Figure 1 is a top view of a mechanicalstoker with the lid open to reveal the swinging bottom. Figure 2 is alongitudinal, sectional view taken through the same. Figure 3 is a crosssectional view taken through the hopper on the line 3-3 of Figure 2.Figure 4 is a cross sectional view taken through the cone portion of theswinging bottom. Figure '5 is a top plan view of the swinging bottom,with Figure 7 is a top plan view of the coal bin adapted to receive myswinging bottom. Figure 8 is a cross sectional view taken through thecoal bin on the line 8-8 of Figure 7. And Figure 9 is a detail side viewof one form of mechanism for actuating the swinging bottom.

In the accompanying drawings illustrating various forms of embodiment ofmy invention, the numeral l designates the hopper of an automatic,underfed stoker. Passing through the lower portion of the hopper I,which will be hereinafter designated the outer hopper, is a feed screwshaft 2 to which is secured a conventional fuel feed screw 3.

Swingingly mounted upon the feed screw shaft 2, near its driven endwithin the outer hopper l, is a bottom 4 which has an end boss portion 5formed with an axial hole through which the shaft 2 projects and uponwhich the boss is free to turn. A gasket 5* surrounds the feed shaft 2between its screw portion and the inner hopper to be hereinafterdescribed.

The'swlnging bottom 4 preferably comprises a single, integral castingwhich includes an integral tion 8 of the cone crusher part of theswinging 4 bottom may be easily detached from the lower half 6 to permitthe ready removal of obstructions, and the making of repairs.

At its feed tube end, the cone crusher part of the swinging bottom isformed with a spherical, annular surface 9 which rests against thespherical annular bearing surface It onthe inside of a housing castingII to hold it concentric with the feed tube I2. To the end of this feedtube nearest the hopper there is demountably secured by screws ii thereduced end'l4 of the housing II that surrounds the crusher cone endmoved, the housing may be slid back over the feed tube to expose theupper half of the cone crusher, to permit its removal.

Ribs, in this instance integral fins iii of spiral form, are provided onthe inner surface oL-th crusher cone sections of the swinging bottom.These fins project from the mouth of the clone to a point near itsdischarge end for cooperation with the feedscrew 3 in dividing intosmaller.

pieces and moving through the cone, lumps of coal or other coarsematerial.

Formed on each side of the swinging bottom 4 is a projecting shaft orledge [1 that is provided with a recess to receive the lower end l8 of ahalf section IQ of an inner hopper 20. Curved clamps 21 secured to thebottoms of the innerhopper sections l9, l9 by bolts 22, engage therounded outer surfaces of the projecting ledges l1, I! on 4 the swingingbottom 4 to assist in hingedly securing the inner hopper sectionsthereto. (See Figure 9.)

inner hopper 20 simultaneously with the feed screw shaft 2, I haveprovided the following means, although any other suitable means may beemployed for this purpose if desired. Refering to Figure 9, the screwshaft 2 carries an eccentric 23 from which there projects outwardly arod 24 pivotally connected to the middle portion of a lever arm 25adapted to be secured at one end to a fixed pivot (not shown). Pivotallysecured to the other end of the lever arm 25 is a link26 that ispivotally connected to the outer end of an arm 21 secured to theswinging bottom .4, whereby when the screw shaft 2 is rotated, it

.will be swung to give a vertical, reciprocable movement to each halfsection l9 of the inner hopper 20 through an arc defined by the movementof its respective ledge l'l.

In addition to its vertical movement, each hopper section 13 receives ahorizontal reciprocating movement by virtue of the arc traversed by itsrespective ledge, so that when one section is raised and drawn in towardthe center, the other section is lowered and thrown out. This movementof the inner hopper sections causes one half of the material carried bythe hopper to be raised and distorted while the other half descends,effecting a cleavage of material directly above the feed screw 3.

In Figures 7 and 8 I have shown my swinging bottom incorporated in acoal bin 28 from which coal is delivered to a furnace 29 by the feedscrew 3 which passes through the cone crusher end of that bottom and thefeed tube l2. Below the rigid open bottom 30 of thecoal bin are inner tothe ledge ends ll 'of the swinging bottom 4. The latteris preferablyswung about the feed shaft 2 by the eccentric means hereinbeforedescribed and shown in dotted lines in Figure 7.

The feed shaft 2 is rotated by a gear 32 secured to its outer end and inmesh with a pinion 33 carried by a shaft 34 driven by a gear (not shown)in a gear box 35.

eWhen employed in a coal bin, my swinging botl'tom will constantlymaintain a seam or cleavage in the coal in a vertical plane extendinglongitudinally with, and directly above, the axis of the feed screw 3 onthe shaft 2.

I do not wish to be limited to the details of construction andarrangement herein shown and described, and any changes or alterationsmay be r made therein within the scope of the subjoined ijclaims.

Furthermore, while my invention is more particularly designed for use inconnection with an automatic stoker, it is equally applicable to thefeeding of any material from a bin or hopper.

Havingdescribed my invention, I claim:

1. A mechanical stoker comprising a hopper, a feed screw shaft withinsaid hopper, means for rotating the feed screw shaft, a bottom pivotallymounted in said hopper for a swinging movement For the purpose ofswingingthe bottom 4 of the about the feed screw shaft, an eccentriccarried by said shaft, a lever arm pivotally secured at one end to saidhopper, a rod pivotally connecting the eccentric and lever arm, and alin'k,pivotally connected between said arm and the bottom to swing thesame when the feed screw shaft is rotated.

2. In a mechanical stoker, a hopper, a feed tube, a feed screw forforcing material from said hopper to the feed tube, a bottom pivotallymounted in said hopper for a swinging movement about the feed screw,means to rotate the feed screw and rock the bottom, a sectional crushercone whose lower half is cast integral with said bottom, and a housingdetachably connected between the feed tube and 'the'hopper and having abearing seat for the feed tube end of said cone, the top section of saidcone being removable for thewithdrawal of obstructions around the feedscrew and the making of repairs.

3. In a mechanicalstoker, a hopper, a' feed tube, a feed screw forforcing material from said hopper to the feed tube, a bottom pivotallymounted in said hopper for a swinging movement a cone extension whoselower half is integral with said bottom, a housing detachably connectedbe tween the feed tube and the hopper and having a bearing seat for thefeed tube end of said cone extension, and fins on the interior of saidcone extension, one section of said cone extension being removable foraccess to the feed screw and fins to remove obstructions therefrom.

' mun H. BEAM.

